There are over one million cancer surgeries per year performed in the United States and nearly 40% of them miss resecting the entire tumor according to the National Cancer Institute Surveillance Epidemiology and End Results report. For example in breast cancer lumpectomies, failure to remove all the cancer cells during the primary surgery (positive margins) occurs approximately 50% of the time and requires second surgeries. Residual cancer in the tumor bed is a leading risk factor for local tumor recurrence, reduced survival rates and increased likelihood of metastases. In addition, final histopathology of the resected tumor misses 25% of the residual cancer left in the tumor bed, which must be addressed with adjuvant medical therapy (e.g. radiotherapy or chemotherapy). This poor performance of pathology is primarily due to a sampling error since only a small fraction of the entire tumor is analyzed.
In a typical solid tumor resection, the surgeon removes the bulk of the tumor and sends it to pathology. The pathologist then samples the bulk tumor in a few locations and image a stained section under microscope to determine if the surgeon has completely removed all of cancer cells from the patient. Should the pathologist find a portion of the stained sample without normal cells bordering the cancerous cells (a diagnostic known in the medical realm as “positive margin”), the surgeon may be instructed to resect more tissue. However this pathology exercise is a time intensive procedure and often takes days for final results to be sent to the physician. Should a pathology report requiring additional resection return after the patient has completed the initial surgery, this may require the surgeon to perform a second surgery.
The current pathology process is not favored for a number of reasons. First, the pathology process relies on sampling a given tumor at certain spatial intervals which may result in missing a critical portion of the tumor and is therefore not a very reliable source of information. In addition, the process disrupts the surgical workflow since the physician and the patient have to wait for the pathology report to return prior to finishing the surgery or return for a second surgery should the pathology process exceed the time window for the first surgery. Leftover cancerous cells in a patient could result in cancer recurrence or additional necessary therapy (e.g. radiation, chemotherapy, etc.). There is a need for a system that improves upon the inefficiencies of the pathology process, reducing second surgeries, cancer recurrence, and additional medical therapy for cancer patients.
U.S. Patent Application publication number 20110104071 describes a system for detecting molecular imaging probes at or near the surface of exposed tissue during surgery, without confocal microscopy and related limitations on the field of view and depth of focus. The system can be used in clinical settings to guide surgery or therapy when localization of the target is important for treatment, such as for example in cancer treatment. The present invention is an improvement in that system, including, but not limited to, an improvement in the molecular imaging probe employed to detect target cells.